PT - JOURNAL ARTICLE ED - , TI - â–¾ Botulinum toxin and dystonias AID - 10.1136/dtb.29.26.102 DP - 1991 Dec 23 TA - Drug and Therapeutics Bulletin PG - 102--103 VI - 29 IP - 26 4099 - http://dtb.bmj.com/content/29/26/102.short 4100 - http://dtb.bmj.com/content/29/26/102.full SO - Drug Ther Bull1991 Dec 23; 29 AB - Blepharospasm is a form of focal dystonia in which there are sustained or frequent bilateral contractions of the orbicularis oculi muscles, causing repetitive blinking (and even virtual blindness). Benign hemifacial spasm (which is unilateral and classified separately from the dystonias) also causes blinking and distressing spasms of the facial muscles. We last reviewed them 3 years ago.1